Well yeah-- and what would be wrong with that? The fact is that Kyuuremu isn't Uber, and while he might have scary ass power, the reason he's not top OU is because all the other dragons have scary ass power too (in addition to a whole bunch of other perks too), no?
Ice/Dragon gives it an advantage against some Rain Dance Sweepers and other weather sweepers (better success against the Sunny Day users than Rain Dance although must watch out for Chlorophyll Sleep Powders) that aren't Kingdra, Kabutops, Abagora, or boosted Shell Breakers (since they will have Rock and Dragon Attacks or +2 Hydro Pumps and such). Must watch out for Charizard and Sleep Poweders, but can handle Venasaur, Tangrowth, etc. I do question why Gorebyss isn't used more (Swift Swim, Shell Break, Surf/Hydro Pump=Good luck) but Kyurem can indeed take a +3 Surf or Icebeam from Manaphy and Ko with Specs Draco Meteor. While I normally like being able to switch moves, we all know the power behind Specs boosted Draco Meteors from 130 SAtk (Latios). if you play in Hail, Blizzard is also a highly powerful option. I don't know what perks most dragons have over Kyurem when they serve in different functions.
Kingdra is a Rain Dance sweeper, a very very dangerous powerful Rain Dancer Poke. It might be useful just to run one to counter other Rain Dance sweepers but outside of Rain Dance, most of the time he really isn't all that powerful when Nattorei can take on his former Dragon Dance Waterfall Outrage set so easily and Scarf Garchomp is back, speedy Doryuzu in sand, etc.
Garchomp is Garchomp. He has Sand hax, Choice Scarf, and Swords Dance to beat people with and a troll 102 base speed outspeeding 101s and lower. He is pretty strong but he has a completely different purpose from Kyurem which means you can't generally compare them but if you want to compare them both using Choice Scarf, Kyurem does have the niche of not being able to be revenge killed by Ice Sharders (unless Garchomp Sand Veil luck kicks in) or other Choice Scarf Icebeamers and most people don't use faster things with Scarf (that are going to ko Kyurem) unless they're weather dancers in which case they will outspeed everything in their appropiate weather anyways. You outspeed Manaphy and can survive and ko and if you don't, you still survive a +3 and ko with a second move unlike Garchomp or Latios (who if Manaphy survives Draco Meteor which it can with invested defense can ohko with +3 Icebeam which is another advantage of being neutral instead of weak to Ice).
Latias is outclassed by both Kyurem, Latios, and every other dragon sweeper without Soul Dew. With Latios, she can't even get the honor of being the fastest dragon with a powerful stab Draco Meteor like in the 4th gen. Being Soul Dew banned (and currently unavailable in 5th gen) the only advantage she does have is Wish and Thunderwave since her other defenses can be done by Kyuremu with that high hp and it can run Reflect/Light Screen as well. As a Wish user, she is weaker than Vaporeon, Heart fish Mamabo, Blissey, Jirachi, and Umbreon for passing wishes. Thunderwave is a surprise but Choice Scarf Garchomp could switch in knowing Thunderwave and beat it. So lol, Kyurem is not the "worst" OU dragon because of being outclassed.
Latios is beastly but Pursuit weakness is annoying. At least Kyurem doesn't have that. Although it is to be noted that both Specs Latios AND Kyurem can 2 hit ko standard Choice Band Scizor with Draco Meteor. Not that Kyurem should want to try that (without any investment Scizor has a 33.33 of ohkoing). But in a way this is a good thing since now that Scizor is so weakened, it can't switch in a second time without dying. Latios can be gutsy and strike since Bullet Punch does only 69.54% but Latios doesn't want to face Tyranitar unless carrying Choice Specs Grass Knot/Surf and hitting it on the switch in. Grass knot ohkoes min/min with Stealth Rock while Surf is a 2 hit ko that also hits Heatran. Since Choice Scarf Tyranitar usage is very low again with better revenge killers, Latios is fairly safe enough to Surf again. Kyurem doesn't like Stealth Rock but because it is lesser used (not gone, just lesser used), improved Wish passing, and Rapid Spinning, Kyurem is safer. Relying on Stealth Rock or one single thing to keep things at bay isn't generally going to help since it is a weakness that once it's gone and you have nothing else, you're going to be in very bad trouble. It could be the same for you but that's why you have multiple things to support.
Sazandora has the same Mach Punch problems as Kyurem. Other than that it is hard to say since Sazandora is sllightly faster, immune to Spikes with Levitate, neutral to Stealth Rock, and carries Fire Blast/Flamethrower. Still, Kyurem is much bulkier and neutral to Ice and Dark/Dragon is a pretty disjointed typing for the most part that seems like it should have been pure Dragon. I don't see why both can't be viable for usage if it wasn't for Latios stealing the spotlight from both of them.
Dragonite has Multi-Scale and defensive sets as well as being very hard to beat with Roost and Multi-Scale which is Light Screen/Reflect at full health. However, it still has a 4x Ice Weakness and the same Stealth Rock weakness as Kyurem. But they have completely different purposes with Dragonite being a very bulky Dragon Dancer, an offensive Dragon Dancer with Multi-Scale, a mixed attacker, Rain abuser (dangerous with Ice attacks and Rain sweepers but...)and a statuser/phazer spikes damage racking abuser. Kyurem has Screens, mixed, and straight out attacking. It is unfortunate for Dragonite it can't have Multi-Scale with Super Power. Dragonite is one of the best dragons but as a special attacker, Kyurem is better.
Crimigan has a niche of being a Choice Band user,Trick Room danger, and abuser of Shed Skin. Lesser seen but potentially dangerous. Different from Kyurem though.
Salamence has gone down because of Dragonite and Garchomp but it still is a decent Dragon Dancer with access to speed, really strong special attack and Fireblast. Different.
Onokonosu has a small movepool as well. It is technically faster but bulkier variants have proven to help surviveability a lot and make it slightly less glass cannon so Kyurem is faster. Plus, it is a physical attacker and Kyurem is a special attacker so you can't compare that. Kyurem has way better resistances. But still, not really comparable.
Flygon...why use it with Garchomp? It is almost completely outclassed by every Dragon. Choice Band is done better by Dragonite, Salamence, Crimigan, Garchomp. Choice Scarf is outrun by Garchomp, Latios, and Latias as well as Kingdra in Rain. Choice Specs...why? The only set it has that isn't outclassed is Roost/Substitute/Toxic/Earthquake which is useable with Levitate and those resistances but it only works on stall and it is beaten by Ballooners, Poison Orb Gliscor, and most everything that isn't using a resisted move.
Other than Sazandora and Latios and occasionally Dragonite, you can't really compare other dragon and specifically say they are better. Kyurem has the honor of being a really powerful Ice/Dragon who is not nearly as bad as everyone says (Utter trash it is not). Plus is pretty viable in Overused and Ubers with coverage on almost everything with Dragon/Ice and resisting Water/Electric/Grass and neutralities to Ice/Fire. Obviously as a Dragon you have a Dragon weakness, it isn't a hard concept to take. Steel weakness can be unfortunate but the only common steel it fears is Scizor since Metagross and Jirachi have lower usages and in Hail, Choice Specs Blizzard can 2 hit ko Metagross with Stealth Rock (damn powerful). Every other steel can't really handle it since most of even the defensive ones are 2 hit koed by Ice attacks which actually is not overlapping (Skarmory and Nattorei resist Dragon but are threatened by the powerful Ice Stab). It does wish for Flamethrower and Earthquake (why the heck does almost every Dragon learn Earthquake but a freaking heavy strong Ice Dragon not? Even the Latis learn Earthquake and they don't seem to weigh that much and levitate?).
They did interesting things this gen, making moves that had been pretty much availabe to everyone, less so. While I guess I understand Flamethrower (it is an ICE dragon) what is with other moves like Earthquake? Although the other Ubers (Reshiram and Zekrom) have other small movepools, this gen they design it so that you don't really need much more than your stab to beat people. Ice/Dragon does hit most types and other than Steel/Psychic or Steel/Bug, it covers everything else with Focus Blast. It still hits neutral and it's stabs are so strong that it can often two hit ko with them even resisted (with Specs and high power). It isn't the slowest Dragon and nothing can for the most part safely switch in. Plus, it is the ULTIMATE Lure and can bring Steels in like no other since nothing else really wants to take a stab. Plus it can go mix if necessary to destroy Blissey (in return to dying to Mach/Bullet Punchers named Breloom and Scizor).
It can survive Roopushin Mach Punch easily (from Guts boosted Mach Punch it takes 64.45-75.7 so only a 7.69% ohko after Stealth Rock) and ohko with Specs Meteor. It also survives Hitmontop Life Orb Mach Punch even with Stealth Rock unless it Fakes Out (which can only be done the first turn Hitmontops out). It can survive Breloom Mach Punch (without Stealth Rock damage) since it does 78.26-92.07%. And all these were min/min! That is how bulky it is. It can only be revenge killed by faster Draco Meteors and Close Combats so there is a slight purpose for Frozen World in that case against the Horses and Infernape and such on the switch in (although that is pretty dumb to switch them in since pretty much nothing safely switches in and can only revenge kill and these aren't the pokes who can switch in). With Wish (Blissey Wish especially) this thing can be INSANELY deadly since Wish would restore it's health, they're down their main counter, and are facing a fast and bulky dragon with insane power breathing down their neck. Most of the other OU dragons can't say the same thing or have same bulk (except Dragonite).
Why this only has 660 (maybe there was a miscalc when they were desgning it to be Uber like the other dragons?) is weird, if this thing had those extra 20 points of speed, this would be Uber without question. Still faster than most and most Sazandora don't run max speed and unless they're Choice Scarf or Choice Specs, they're not going to outrun so would be destroyed by Kyurem. You can't lump all dragons together as one as many have different purposes and Kyurem's is insane special attack power that is only resisted by one type and incredible bulk. It isn't nearly as weak as people here are making it out to be.
Again, min/min at full health survives Roopushin, Hitmontop, Breloom, Infernape, etc Mach Punches. It MIGHT survive Choice Band Scizor at full health (although it'd be useless later since the likelyhood of it switching in is small, but it will make good sacrifice fodder if needed to get somethin in then) if you're a gambler type. With invested defenses and Reflect, Kyurem will and threaten back. Kyurem can support the team with screens, wall breaking, and luring. It isn't "useless" or "terrible" like people are saying.